Marine waste disposal apparatus

ABSTRACT

A filter-adsorption media, such as activated carbon, is supplied to one end of a screw conveyor having a variable pitch along its length with the greater pitch being at the supply end. Sewage, such as from a marine toilet, is passed through a macerator and chemically treated before being introduced into the central portion of the screw conveyor to be mixed with the filteradsorption media and compacted as the screw conveyor is rotated. The compacting produces a mixture of filter-adsorption media and sludge at the discharge end while the liquid is passed through the conveyor in counter-flow relationship, to the incoming filter-adsorption media and through the filter-adsorption media, and then to a discharge.

United States Patent [1 1 [111 3,786,923

Schmidt Jan. 22, 1974 1 MARINE WASTE DISPOSAL APPARATUS PrimaryExaminer-Samih N. Zaharna Assistant Examiner-Thomas G. Wyse F S h d A dP [75] Inventor erenc J c m r more a Attorney, Agent, or FzrmD. BernerSmythe et al. [73] Assignee: Ametek, Inc., New York, NY.

[22] Filed: July 26, 1971 [57] ABSTRACT [21] Appl. No.: 166,132 Afilter-adsorption media, such as activated carbon, is

supplied to one end of a screw conveyor having a variable pitch alongits length with the greater pitch being 2% 8 210/152 6 at In? supplyend. Sewage, uch as f om a marine toi. u g let, is passed through amacerator and chemically [58] Field of Search ..210/39, 40, 75, 77, 226,V

210850452 152 153 396 397 treated before being introduced into thecentral portion of the screw conveyor to be mixed with the filter- [56]References Cited adsorption media and compacted as the screw conveyor ISrotated. The compacting produces a mixture UNITED STATES PATENTS offilter-adsorption media and sludge at the discharge 1,604,652 10/1926Mannin 210/75 X end while the liquid is passed through the conveyor incounter-flow relationship, to the incoming filterannmg 3,677,404 7/1972Staffin 210/75 x 233E322, zg i 23 212??? the filter adsorpt'on 1 Claim,3 Drawing Figures T0 DISCHARGE CONTR' L lLTER-ADSOR PTION MEDIA SUPPLYFROM TOILET PATENTEB JAN 22 I974 SNEEI 2 BF 20 T0 DESCHARGE FROM TOILETLTER-ADSOR PTION MEDIA SUPPLY V I7 CONTR'L \x -F ILTER ABSORPTION uEmAa'SLUDGE STORAGE INFLUENT /REMOVABLE RECEIVING CONTAINER INVENTORFEA'EA/C JCI/M pr TORNEYS MARINE WASTE DISPOSAL APPARATUS Anincreasingly serious ecological and health problem has arisen in manybodies of water as a result of the discharge of raw sewage fromrecreational water craft equipped with marine toilets. In some coastalareas, the increasing number of such boats has compounded the problem tosuch an extent that regulations have been placed into force requiringsuch boats to be equipped with holding tanks or apparatus for treatingall waste water discharged overboard. Not only must the waste be treatedunder proposed standards, but it must be effectively treated so that theeffluent discharged overboard meets higher standards than available withpresent apparatus.

It is one of the objects of the present invention to provide improvedwaste disposal apparatus for marine toilets and the like.

It is another object of the invention to provide a marine waste disposalapparatus which requires a minimum of space, is automatic in operation,and needs a minimum of maintenance and cleaning.

It is a still further object of the invention to provide a marine wastedisposal apparatus which is simple in construction and reliable inoperation over long periods of time.

A still further object of the invention is to provide a method andapparatus for treating sewage or waste material in a superior manner.

According to one aspect of the present invention, a marine waste orsewage disposal apparatus may comprise a housing having a conveyortherein, such as a screw conveyor with a varying pitch along its length,with the end of the screw conveyor having a greater pitch at the supplyend and a smaller pitch at the other or discharge end. The screwconveyor is rotated by suitable means, as may be desired and sewage isintroduced into the housing at substantially the central portion of thescrew or between the supply and discharge ends. A supply of afilter-adsorption media, such as activated carbon, is located adjacentthe supply end of the screw and fed thereto. At the discharge end of thescrew, there are provided means for receiving and storingfilter-adsorption media and sludge resulting from the compacting ofmedia and filtering of the sewage as the mixture is moved along by thescrew toward its discharge end. The sewage moves, in counter-flowrelationship through the conveyor screw to the supply end of the screw,and then through the media supply to an effluent discharge. Compactingof the media and sludge causes the liquid of the effluent to move incounter-flow relation to the filter-adsorption media and therethrough.

In the process of the present invention, the sewage is introduced into afilter-adsorption media. The mixture of sewage and media is compactedwhile moving the mixture in one direction so as to form afilteradsorption media and sludge mixture. Effluent moves incounter-flow relationship through a supply of a filteradsorption mediato a discharge zone for the effluent.

The sewage can be treated in a maceratorchlorinator," such as now inuse, before it is fed to the screw conveyor.

Other objects, advantages and features of the present invention willbecome apparent from the accompanying description and drawings, whichare merely exemplary.

In the drawings:

FIG. 1 is a block diagram illustrating schematically the sewagetreatment apparatus and method according to the present invention;

FIG. 2 is a schematic drawing of the sewage treatment apparatus; and

FIG. 3 is a schematic side elevational view of a sewage treatmentapparatus according to the present invention and particularly adaptedfor use in limited space.

Preceeding next to the drawings wherein like reference symbols indicatethe same parts throughout the various views, a specific embodiment ofthe present invention will be described in detail.

As may be seen in FIG. 2, one form of the filtrationadsorption apparatuscomprises a unit, indicated generally at 10, having housing 11 in whichis rotatably mounted a screw conveyor 12 having a varying pitch thereonwhich progressively becomes smaller in the direction from supply end 13of the conveyor to its discharge end 14. The conveyor is mounted uponshaft 15 which is drivingly connected to a suitable source of power suchas an electric motor 16. A suitable control 17 can be connected to theelectric motor 16 to operate the motor on an intermittent or any desiredbasis. As an alternative, an automatic control may be provided whereinthe electric motor is operated upon each use of the marine toilet orwhen a predetermined quantity of sewage has been introduced into thehousing.

FIG. 1 is a block diagram illustrating the use of the invention. Thesewage or waste from a toilet or the waste water can be fed to aconventional macerator and chemical treating device. As an example,macerator-chlorinators are well known. In the present invention, thechemical additive should include a flocculating chemical, such as alumor ferric chloride, as well as the chlorinating chemical, such ashypochlorite. The waste stream from the macerator-chemical treatmentdevice 23 is fed to filtration-adsorption unit 10. The sewage willremain in the macerator-chemical unit 23 until the next flush so thatthere will be adequate time for treatment before reaching thefiltration-adsorption unit 10. Additionally, coarse sand or a filter aidcan be added. a

A filter-adsorption media supply canister 18 is positioned on housing 11adjacent the supply end of the screw and contains filter-adsorptionmedia 19, such as activated carbon. The supply canister or means is alsoprovided with a discharge opening 20 through which effluent isdischarged in a manner to be presently described.

At the other end of the housing 11 there is provided a receivingcontainer or chamber 21 which may be removable, which receives themixture of filteradsorption media and sludge from the discharge end 14of screw conveyor 12. The receiving container or canister 21 when fullshould have such a weight so as to facilitate easy handling but whichwould necessitate only one or two removals during a boating season.

The sewage to be treated flows from a marine toilet through a line 22into a macerator 23 into which hypochlorite and flocculating agents arefed, as known in the art, so that the sewage is both macerated andchemically treated before being introduced through line 24 atsubstantially the central portion of the screw conveyor l2.

In FIG. 3, there is shown a modification which comprises the samecomponents as in the apparatus of FIG. 2, but the components arepositioned so that the screw conveyor 12A positively displaces themixture of filteradsorption media and sewage upwardly to eventually dumpthe mixture from the discharge end 14A into the removable receivingcontainer 21A. Simultaneously, the effluent will flow downwardly withinthe housing 11A, into the media supply 18A, and outwardly through theeffluent discharge 20A. Since the passage of the waste stream from thetoilet to the apparatus is rapid because of the pressure supplied by theusual pos itive displacement flushing pump, the screw conveyor needoperate during flushing only. The media supply container 18A is providedwith a charging door 25.

In the operation of the apparatus, it is first necessary to prime thedischarge end 14 of the housing with a small quantity of thefilter-adsorption media to prevent the raw sewage effluent from flowingdirectly into the discharge container 21.

The influent enters housing 11 after being macerated and chemicallytreated and mixes with filter-adsorption media fed from the supply end13 of the conveyor. Upon rotation of conveyor 12, the filter-adsorptionmedia and sludge from the sewage or waste becomes progressivelycompacted by the increasingly smaller pitch of the screw conveyoradjacent the discharge end 14. The mixture of fluid-adsorption media andsludge is rendered substantially impermeable to liquid in the sewage bythe sewage solids trapped in the filteradsorption media. This causes theeffluent liquid to flow through the loosely compacted filter-adsorptionmedia toward the left end or supply end of the conveyor. Thus, theeffluent or liquid moves in counterflow relationship to the movement ofthe filteradsorption media.

As the effluent moves through the housing 11 of the unit toward theeffluent discharge, the suspended solids are removed by a process ofin-depth filtration. The clear liquid is then exposed to the supply offilter adsorption media 19 in the supply canister 18 for a sufficientperiod of time to reduce the BOD to acceptable levels. The effluent isthen discharged at 20 because of displacement by the next flush volume.

As influent from the line 24 continues to flow toward the effluentdischarge or the left-hand end of the conveyor (FIGS. 2, 3), thefilter-adsorption media in the immediate area of the influent port 24will become clogged with sewage solids and gradually become impermeable.At this time, screw 12 is rotated by the electric motor 16, and theclogged media is advanced toward the right (FIGS. 2, 3), which forcesthe media located therein into disposal canister 21. As the screw isrotated, fresh media is drawn from the supply canister 18 into thehousing 11 of the unit. The cycle is now ready to be repeated.

The construction of the filter-adsorption unit disclosed herein can berapidly disassembled for maintenance and cleaning. The unit isinherently fail-safe since, if the electric motor should fail tooperate, the system will clog with sewage solids and prevent the passageof sewage to the effluent discharge port. A small screen may be providedin the effluent discharge port 20 to prevent operation of the unitwithout a suitable charge of filter-adsorption media. There can be nofiltration without media present. This will cause the screen to clograpidly if exposed to raw sewage and prevent the discharge of untreatedeffluent. The screw conveyor arrangement and positioning, whether movingor not, results in surface removal of the column of filter-adsorptionmedia including sludge within the housing. When the conveyor is moving,the media is scraped from the interior walls of the housing.

As a modification, the screw conveyor 12 can be operated in response toa pressure sensitive switch which is actuated when clogging of thefilter surface occurs. This modification would reduce thefilter-adsorption media consumption since particulate suspended solidsare not introduced into the marine toilet with each usage. Further,instead of an electric motor, a hand crank could be used. Also, it canbe used for purposes other than marine disposal.

As an example, a device built in accordance with the principles of theinvention has been found to reduce raw sewage from 9,500 COD (ChemicalOxygen Dernand), an average of 89 percent reduction. As another example,raw sewage with a 16,300 COD was reduced an average of 99 percent.

Thus, it can be seen that the present invention has disclosed anapparatus and process wherein the waste from a marine toilet or othersewage source is subjected to a combined filtration and adsorptionprocess which removes the larger percentage of the matter from theincoming waste stream and renders the remaining material inoffensive andsuitable for overboard discharge. The apparatus is fail-safe in design,simple in construction, easily installed and requires no specialtraining for its use. Further, the apparatus give full consideration tothe unique requirements of water craft with respect to safety,reliability, performance under all conditions of pitch and roll andsimplicity of operation. Since the apparatus employs a minimum of movingparts, the invention is characterized by a high degree of reliability.

It will be understood that various details of construction andarrangement of parts may be made without departing from the spirit ofthe invention except as defined in the appended claims.

What is claimed is:

1. In a sewage disposal apparatus for waste material from a vehiculartoilet containing sludge, in combination including a housing,filter-adsorption media supply means connected to said housing forreceiving particulate media, discharge means connected to said housingfor discharging filter-adsorption media and sludge thereform, influentsupply means connected to said housing between said supply means andsaid dis charge means for feeding waste material to be treated thereto,conduit means connecting said toilet and said influent supply means,conveying means in said housing carrying said filter-adsorption mediafrom said supply means toward said discharge means and past saidinfluent supply means, said conveying means being a screw withprogressively smaller pitch toward the discharge means to progressivelyincrease the compactness of said filter-adsorption media and sludge asit moves past said influent supply means to the discharge means, so thatthe liquid portion of the influent will move countercurrent through saidfilter-adsorption media in the area of the larger screw pitch before theinfluent supply means and where the media is less compact to thefilter-adsorption media supply means, the sludge being filtered thereby,means for rotating said screw, and the filter-adsorption material andsludge being increasingly compacted as they move beyond the influentsupply means toward the discharge means and are discharged therefrom,the compaction being such that the liquid portion of the influent supplyis directed toward said media supply means and is filtered by thefilter-adsorption material.

1. In a sewage disposal apparatus for waste material from a vehiculartoilet containing sludge, in combination including a housing,filter-adsorption media supply means connected to said housing forreceiving particulate media, discharge means connected to said housingfor discharging filter-adsorption media and sludge thereform, influentsupply means connected to said housing between said supply means andsaid discharge means for feeding waste material to be treated thereto,conduit means connecting said toilet and said influent supply means,conveying means in said housing carrying said filter-adsorption mediafrom said supply means toward said discharge means and past saidinfluent supply means, said conveying means being a screw withprogressively smaller pitch toward the discharge means to progressivelyincrease the compactness of said filter-adsorption media and sludge asit moves past said influent supply means to the discharge means, so thatthe liquid portion of the influent will move countercurrent through saidfilter-adsorption media in the area of the larger screw pitch before theinfluent supply means and where the media is less compact to thefilteradsorption media supply means, the sludge being filtered thereby,means for rotating said screw, and the filter-adsorption material andsludge being increasingly compacted as they move beyond the influentsupply means toward the discharge means and are discharged therefrom,the compaction being such that the liquid portion of the influent supplyis directed toward said media supply means and is filtered by thefilter-adsorption material.